1. Field of the Invention
This invention relates to foldable and extensible structures and, more particularly, to a foldable and extensible structure fabricated from one or more base modules, each base module being configurated from six rigid members flexibly interconnected end-to-end by swivels into a closed configuration generally approximating a double triangle in appearance when folded flat and having intersecting rigid members pivotally secured.
2. The Prior Art
Numerous applications can be found for foldable and extensible structures including, for example, pedestals, stools, trusses, antennae, extension arms, and the like. One familiar form of an extensible arm structure is a common "scissors" extension arm. The "scissors" extension arm involves a first pair of pivotally joined rigid members. Additional pairs of rigid members may be pivotally joined to the end of the first pair and each successive pair. Lateral movement of the free ends of the pair of rigid members imparts a corresponding movement to the pivotally interconnected pairs of rigid members resulting in a linear contraction and/or expansion of the extension arm. This is a well known apparatus and is found in numerous applications. However, this particular "scissors" extension arm is generally considered to be a two-dimensional configuration since all of the pivotal movement occurs in the same general plane and, therefore, lacks the necessary structural stability for various applications.
With respect to structural stability, it is well known that a generally triangular or three-dimensional basic structural configuration has desirable dimensional stability. It would, therefore, be an advancement in the art to provide a foldable and extensible structure fabricated with a generally triangular basal configuration and which is three-dimensionally foldable and extensible. An even further advancement in the art would be to provide an antenna-like structure which is foldable into a relatively flat configuration while being extensible into a structure having a significant ratio of extended length to folded length. Another advancement in the art would be to provide a novel basal module which is foldable and extensible and can be interconnected to form a plurality of foldable and extensible structures. Such a foldable and extensible structure is shown and claimed herein.